<!DOCTYPE html>
<html>
<head>
  <title>IE 7/8 Event Param Test</title>
  <script>
    function div1Click(e)
    {
      e = window.event;
      e.div1 = "div1";
      console.dir(e);
      console.log('Is same? ' + ((window._event == e)? 'true': 'false'));
      window._event = e
    }
    function div2Click(e)
    {
      e = window.event;
      e.div2 = "div2";
      console.dir(e);
      console.log('Is same? ' + ((window._event == e)? 'true': 'false'));
      window._event = e;
    }

    function init()
    {
      var div1 = document.getElementById('div1');
      var div2 = document.getElementById('div2');
      div1.attachEvent('onclick', div1Click);
      div2.attachEvent('onclick', div2Click);
    }
  </script>
</head>
<body onload="init()">

<div id="div1">
  <div id="div2">A line of text</div>
</div>

</body>
</html>